Abstract: The invention provides a method for making a novel porous sintered material according to an HIP (Hot Isostatic Press) molding technique usually used for the purpose of obtaining defect-free and highly dense powder products. In the method of the invention, a capsule containing a starting powder in a hermetically sealed condition is heated according to a predetermined temperature pattern and is also subjected to hot isostatic pressing while a pressure is arrived at a maximum pressure level substantially in coincidence with commencement of a sintering temperature-applying period in the temperature pattern and is gradually lowered from the maximum pressure level during the sintering temperature-applying period. By the method, excessive densification is suppressed and the resulting sintered material has a required porosity and is provided with pores open to outside in the inside thereof, along with good strength and surface processability.

Abstract: An impact crushing machine provided with easily repairable strikers fixedly arranged along the circumference of a rotor at regular angular intervals so as to extend radially of the rotor. A plurality of seats fixedly mounted respectively with striking chips formed of a durable hard material such as a hard metal are arranged in lines and rows on and detachably fixed to the radially outer end of the striker for individual replacement. When the striking chip is abraded to an unusable extent, the seat mounted with the worn striking chip and a seat fixedly mounted with an unworn striking chip can be interchanged for the further use of the striker, so that the frequency of replacing the heavy striker with a new one is reduced and the operating cost of the impact crushing machine is reduced.

Abstract: A carbide tip is provided at a charge stock discharge opening of a rotor in a crushing apparatus. The dimension of the carbide tip in the inner circumferential direction of the rotor is set to 1/2 or more of a maximum particle size of the charge stock. Furthermore, another dimension of the carbide tip is set to 1/2-2 times the maximum particle size of the charge stock. A groove is formed at or near a bonded portion between the carbide tip and a base material of an end blade, so as to avoid stress concentration at the bonded portion.

Abstract: In a method for fabricating a brazed aluminum fin heat exchanger comprising a pair of brazing sheets each consisting of a core sheet and a cladding of brazing material disposed on either side of said core sheet and a corrugated fin interposed between the brazing sheets and brazed thereto, an improved process comprises making at least the fin of a heat-treatable (age-hardenable) aluminum alloy in the Al-Mg-Si system containing 0.15 to 0.4% copper, assembling the fin with said brazing sheets into a brazed aluminum fin heat exchanger unit, maintaining the heat exchanger unit at a temperature between 500.degree. C. and 570.degree. C. for a time from 30 minutes to 4 hours, quenching the solution-treated unit to room temperature under cooling conditions which provide a cooling rate between 2.8.degree. C./min. and 50.degree. C./min. down to 200.degree. C. and thereafter, age-hardening the quenched heat exchanger unit. The above heat-treatable aluminum alloy in the Al-Mg-Si system is AA 6951 or AA 6061.